Diagnostic MRI Score to Differentiate Susac Syndrome from Primary Angiitis of the Central Nervous System and Multiple Sclerosis.

OBJECTIVE: Susac syndrome (SuS), multiple sclerosis (MS), and primary angiitis of the central nervous system (PACNS) present diagnostic challenges due to overlapping clinical features. We aimed to enhance diagnostic precision by developing the SPAMS (SuS, PACNS, MS) score, a practical radiological tool. METHODS: This multicenter study included 99 patients (43 SuS, 37 MS, 19 PACNS) from South American countries. Relevant MRI features were identified through an elastic-net model determined key variables. RESULTS: The SPAMS score assigned 2 points for snowball lesions, 1 point for spokes-like lesions, or if there are more than 4 lesions in the corpus callosum, corpus callosum involvement, or cerebellar involvement. It subtracted 1 point if gadolinium-enhancing lesions or 4 points if Dawson's fingers are present. Bootstrapping validated the optimal cutoff at 2 points, exhibiting a diagnostic performance of area under the curve = 0.931, sensitivity = 88%, specificity = 89%, positive predictive value = 88%, negative predictive value = 89%, and accuracy = 88%. INTERPRETATION: When specific MRI findings coexisted, the SPAMS score differentiated SuS from MS and PACNS. Access to MRI and standard protocol sequences makes it a valuable tool for timely diagnosis and treatment, potentially preventing disability progression and severe clinical outcomes. ANN NEUROL 2024;96:846-854.

Writing tremor secondary to ischemic stroke: a report on a case with a remarkable response to topiramate.

UNLABELLED: Writing tremor (WT) is a task-specific tremor that occurs only or mostly while writing with the dominant hand. Secondary cases are extremely uncommon. We report on a patient who, after developing a WT after an ischemic stroke, had a remarkable response to topiramate (TPM). CASE: A 65-year-old right-handed man with a history of arterial hypertension, dyslipidemia, and coronary heart disease presented dizziness and headache followed by a loss of consciousness and then a right hemiparesis. He regained his strength on the fifth day. Fourteen days after stroke, he developed a WT as well as other complications with activities such as welding (he is a welder) and using a spoon. He was treated with 50 mg/d of TPM with marked improvement in WT. A few weeks after TPM was discontinued, the WT symptoms reappeared and he was retreated, showing the same beneficial reaction.Electromyographic record showed a 5- to 6-Hz tremor in his right hand, and a magnetic resonance imaging showed bilateral small frontoparietal subcortical infarcts. CONCLUSIONS: Primary WT pathophysiology is not well known, and secondary WT as a result of stroke is even less considered. Although patients with essential tremor benefit with TPM and WT could be a variant of essential tremor, we used TPM with our patient and there was a marked benefit.